[baseline=(a1)]

(a1) ;
[right=1cm of a1,square dot, red ] (a2) ;
[below= 0.2cm of a2] (c1) \(Q_{ij}\) ;
[right=1cm of a2 ] (a3);
[above=1cm of a2] (b2);
[left=0.5cm of b2] (b1);
[right=0.5cm of b2] (b3);
[left=0.4cm of b2] (b4) \(a, p_2\) ;
[right=0.1cm of b3] (b5) \( p_1\) ;
* 
(a1)– [double,thick] (a3),
(b1) – [boson ,red] (a2),
(b3) – [scalar ,blue] (a2)
;
   = 
-i2 (d-2) 2 Qab (2 (d-1) p20 p1b+(d-2) p10 p2b)

In Eq.(111) of [1]} the ellipses denote higher order multipoles coupled to 2 sigma fields.
